The proposed research will develop a psychometrically sound measure of functional social support tailored to the needs of individuals with serious mental illness (SMI). The specific aims of this mixed-methods study are: (1) to define an empirically-based typology of functional support for persons with SMI, and (2) to develop and pilot a psychometrically sound SMI- specific measure of functional support. For Aim 1, data will be collected on SMI-specific functional support needs via focus groups conducted with three constituencies of stakeholders: 32 support receivers (persons with SMI), 32 formal support providers (case workers), and 32 informal support providers (family/friends). Employing a grounded theory approach, the PI will then use the data collected from the focus groups to implement Aim 2, the construction of an initial pool of items, which be refined with guidance from an expert review panel, and tested using exploratory structural equation modeling (ESEM) and preliminary psychometric validation studies with 300 SMI participants. The instrument produced through this work will ultimately: (1) provide a tool for researchers to investigate the impact of functional support on buffering chronic SMI stressors (e.g., stigma, isolation, illness management), raising quality of life, and reducing morbidity and mortality among the SMI population; (2) assist service providers in better identifying individual support needs for clinical intervention; (3) add to the growing body of research on disease-specific support measurement; and (4) contribute to establishing standards to address the social support needs of individuals with SMI and to inform national mental health care policy. Additionally, in keeping with the objectives of the AREA program, the project will provide biobehavioral research training opportunities for students, inform the existing curriculum by further emphasizing the connection between research and clinical practice, and enhance the development of research infrastructure at a comprehensive, urban, publicly-funded master's granting institution serving a highly diverse student population. PUBLIC HEALTH RELEVANCE: The proposed research is one of the first studies to identify and measure functional social support specifically among persons with serious mental illness (SMI). It will increase our knowledge of the particular types of social support which are most beneficial for individuals with SMI. The tool created through this study will impact national mental health care policy and, more immediately, people with SMI who access community mental health services, along with their support providers. Results will contribute to the development of new interventions to reduce health disparities by reducing the risks for morbidity and mortality which disproportionately impact persons with SMI.